docs: def close(self):
          """Commit changes and close the database."""
          import sys, os
          for store in self.stores:
              if hasattr(store, 'save'):
                  store.save(reimport=False)
              path, filename = os.path.split(store._filename)
              modname = filename[:-3]
              if modname in sys.modules:
                  del sys.modules[modname]
          super().close()